Passing the limit of electrodeposition: 'Gas template' H2 nanobubbles for growing highly crystalline nanoporous ZnO

► Controlled porosity of highly crystalline ZnO layers by electrochemical deposition. ► Growth mechanism proved by combining cyclic voltammetry with SEM, HRTEM, GDEOS and XRD. ► Controlled H2 nanobubbles generation during electrochemical deposition. ► Solid state DSSC based on porous ZnO photoanodes, C220 dye and CuSCN hole collector. ► Passing the limit of electrodeposition in aqueous solution.